Various means have heretofore been proposed for strengthening the end walls of paperboard containers in the regions above the handholds, in the interests of thereby improving the rigidity of the carton and increasing the resistance of the raw edges of the handhold against tearing when the loaded container is held by the handhold(s).
According to CA 1,004645, a handhold is beneficially constructed by having a bi-layered flap fold back on itself, as is shown in FIGS. 5 and 6 of this CA patent. The end result presents a relatively broad, curved surface along the upper reaches of the handhold, to facilitate the comfort of the holder.
U.S. Pat. No. 2,710,135, proposes that an elongated strip of light weight board be affixed above the handhold opening. As shown best in FIGS. 2 and 3 of the U.S. Pat. No. 2,710,135, the strip is adapted to engage the handhold closure flap, once same is broken away from the surrounding paperboard wall. This construction is asserted to reduce the tendency of the raw edges of the handhold to tear. Moreover the construction is claimed to provide a relatively broad smooth surface at the upper edge of the handhold for easier gripping, handling and carrying the container, all without injury to the hand.
CA 1,034,098 discloses a similar construction, wherein the multiple layers of the fibre board subtending the upper edge of the handhold, forces the inwardly bent flap to curve upwardly, in a rounded, easily graspable shape.
CA 740,309 provides a similar construction, but includes a further refinement in which the free, inwardly swinging flap is adapted to abut against the inner surface of the top of the carton. When so engaged, the flap constitutes a diagonal span between the carton top and end walls, and provides a support surface for ease of grasping. Moreover, it is conceivable that at least some of the carton load is thereby distributed to the top panel of the carton, thereby unloading some of the tearing moments that would otherwise act along the end wall panels. This arrangement is best seen in FIG. 5 of this patents drawings.
CA 650,568 discloses a handhold arrangement in which the free edge of the flap is folded by being pressed against the body of an adjacent bottle. As the flap is pushed progressively further into the container, the apex of the bend formed in the flap engages the container, just at or below the container's crown. In this arrangement, the flap bridges between the container engagement and the end wall to provide a more graspable surface, as well as protection for the holder's hand, against scratching along the serration of the bottle crown's skirt.
Despite these and other attempts, however, there remains an unsatisfied need in the art for handhold constructions which lend themselves to user comfort and improve the physical integrity of the carton.